The present invention relates to an extruder, and more particularly to an extruder for continuously extruding thermosetting resins.
Hitherto, the continuous extrusion of thermosetting resins had never been practised. That is, until the present time, thermosetting resins had generally been shaped in the following manner. First, the resins were preliminary kneaded with the addition of fillers, plasticizers, pigments, reinforcing material, etc. to produce a so-called premix, and later this premix was shaped separately by a press method or an injection molding method in a batch manner. Thus, thermosetting resins have been conventionally shaped in two steps.
However, in accordance with the recent development of products with new shapes and their uses such as profile-shaped products, rod-shaped products, etc., it has become the industry's strong desire to realize an apparatus which makes it possible to continuously knead thermosetting resins with additives and extrude them into shapes without requiring previously prepared premixes.